The present invention relates to the general domain of combustion chambers of a turbine engine. It relates more particularly to the wall of an annular combustion chamber which is intended to connect transversely the longitudinal walls of the said chamber.
Typically, an annular combustion chamber of a turbine engine is formed from two longitudinal annular walls (one internal wall and one external wall), which are connected upstream by a transverse wall, likewise annular, forming the base of the chamber.
The base of the chamber is provided with a plurality of essentially circular apertures which are distributed regularly over the whole of the circumference. Installed in these apertures are injection systems which mix the air and the fuel. This pre-mixture is intended to be burned in the interior of the combustion chamber.
In order to protect the base of the chamber against the very high temperatures of the gases deriving from the combustion of the air/fuel mixture in the combustion chamber, deflectors which form heat shields are likewise mounted in each aperture of the base of the chamber around the injection systems.
The base of the chamber generally has a plurality of multi-perforation holes which are created in the areas opposite the deflectors. These multi-perforation holes are passages for the air which is intended for cooling the deflectors by impact.
In addition to this, the base of the chamber has the shape of an essentially flat ring, which is centred on the longitudinal axis of the turbine engine. This may be either perpendicular to the longitudinal axis of the turbine engine or inclined (towards the inside or the outside) in relation to this axis.
Likewise, the deflectors are generally in the form of a metal sheet of approximately rectangular shape, which is centred on the axis of symmetry of the injection system and which is soldered to the base of the chamber.
In the situation in which the base of the chamber is inclined in relation to the longitudinal axis of the turbine engine, it has the shape of a truncated cone with the axis of symmetry of the injection systems directed towards the inside or the outside. In operation, the result of this is that the distance separating the base of the chamber from each deflector mounted in the apertures is not constant when the axis of symmetry of the injection systems runs out of the vertical. In addition, cooling by multi-perforation of the deflectors is not homogenous, which leads to substantial deterioration of the deflectors, which is particularly prejudicial to the service life of the combustion chamber.